Preparative separation-purification systems using liquid chromatographs are used in the pharmaceutical fields or similar fields in order to collect samples for creating a library of various kinds of chemically synthesized compounds or analyzing the details of such compounds. Conventional examples of preparative separation-purification systems are disclosed in Patent Documents 1 and 2 as well as other documents.
In these apparatuses, target components (compounds) in a sample solution are temporally separated by a liquid chromatograph. The separated target components are introduced into respective trap columns and temporarily captured therein. Subsequently, a solvent (eluting solvent) is supplied to each trap column to quickly elute the component from the trap column and collect it in a container. Thus, a plurality of solutions, each of which contains one target component at a high concentration, are collected in respective containers. These separately collected solutions are then subjected to a vaporizing and drying process to remove the solvent and collect the target components in solid forms.
In the previously described type of preparative separation-purification system, a movable collecting mechanism is used to sequentially elute target components from a plurality of trap columns and collect each eluate in a different container.
FIGS. 3A and 38 show one example of such a collecting mechanism. Although only one pair of trap column 121 and the collection container 142 is shown in FIGS. 3A and 3B, there are actually multiple pairs of trap columns 121 and collection containers 142 arranged in the direction perpendicular to the drawings sheet (i.e. the Y-direction in FIGS. 3A and 38). Each trap column 121 is almost vertically held, with the inlet end directed downward and the outlet end upward.
This collecting mechanism includes a tube 132 through which a liquid is to be passed, a needle 131 connected to one end of the tube 132, and an ejection nozzle 134 connected to the other end of the same tube 132. Both the needle 131 and the ejection nozzle 134 have an inner passage for allowing the liquid to pass through. The needle 131, the tube 132 and the ejection nozzle 134 form a collection passage for guiding an eluate from one trap column 121 into one collection container 142. The tube 132, the needle 131 and the ejection nozzle 134 are supported by a fraction collector head 137, which can be moved vertically (i.e. in the Z-direction in FIGS. 3A and 3B) as well as horizontally (i.e. in the X and Y directions in FIGS. 3A and 3B) by means of a drive mechanism (not shown).
By this collecting mechanism, an eluate from the trap column 121 is collected in the collection container 142 as follows: Initially, the fraction collector head 137 is horizontally moved so as to bring the needle 131 to a position directly above one of the trap columns 121. This operation simultaneously brings the ejection nozzle 134 to a position directly above one of the collection containers 142. From this position, the fraction collector head 137 is lowered to a level where the needle 131 is inserted into the needle port 123 provided at the outlet end of the selected trap column 121, and simultaneously, the ejection nozzle 134 is also inserted into the selected collection container 142 (FIG. 3A). As a result, the outlet end of the trap column 121 is connected to the collection container 142 through the collection passage. In this state, an eluting solvent is introduced from the inlet end of the trap column 121, and an eluate from the same column 121 (i.e. the eluting solvent containing a target component) is collected in the collection container 142.
After the collection of the eluate is completed, the supply of the eluting solvent to the trap column 121 is discontinued, and the fraction collector head 137 is moved upward. As a result, the needle 131 is removed from the needle port 123 of the trap column 121, and simultaneously, the ejection nozzle 134 is removed from the collection container 142 (FIG. 3B). Subsequently, the fraction collector head 137 is moved so as to insert the needle 131 and the ejection nozzle 134 into the next trap column and the next collection container, respectively, to perform collection of an eluate from this next trap column.